In 1951 Prime Minister
Mohammed Mosaddeq received the vote required from the parliament to nationalize the British-owned oil industry, in a situation known as the
Abadan Crisis. Despite British pressure, including an economic blockade, the nationalization continued. Mossadegh was briefly removed from power in 1952 but was quickly re-appointed by the shah, due to an overwhelming majority in parliament supporting him, and he, in turn, forced the Shah into a brief exile in August 1953. A military coup headed by his former minister of the Interior and retired army general
Fazlollah Zahedi, with the active support of the intelligence services of the British (MI6) and US (CIA) governments - including mass propaganda leaflet dropping (slogans such as; "Up with Communism, Down with Ala" and "Down with Islam, up with Communism" designed specifically to turn the population against Mossadegh, as well as the agents of CIA and MI6 (dressed as Mossadegh supporters) spurting machine guns into crowds (known as
Operation Ajax), forced Mossadegh from office on
August 19. Mossadegh was arrested and tried for treason by an un-official military tribunal, (Mossadegh was imprisoned and his foreign minister, Hossein Fatemi, executed) while Zahedi succeeded him as prime minister, and suppressed opposition to the Shah, specifically the National Front and Communist Tudeh Party.
In return for the US support the Shah agreed, in 1954, to allow an international consortium of British (40% of shares), American (40%), French (6%), and Dutch (14%) companies to run the Iranian oil facilities for the next 25 years. The international consortium agreed to a fifty-fifty split of profits with Iran but would not allow Iran to audit their accounts to confirm the consortium was reporting profits properly, nor would they allow Iran to have members on their board of directors.